Quantum computing harnesses the laws of quantum mechanics to solve complex problems too difficult for classical computers. A qubit, the basic unit of information in a quantum computer, can exist in superpositions of states allowing quantum computers to test an exponential number of solutions simultaneously. This enables quantum algorithms to find solutions to problems like protein folding that would take classical computers thousands of years to solve. While quantum computing promises vast speedups, challenges remain in developing algorithms, maintaining the extremely cold temperatures needed, and scaling to larger numbers of qubits.

1. Quantum Computing
Sandeep Vishwakarma

2. CONTENTS
1 Introduction
2 Need of Quantum computation
3 Special about Quantum computer
4 Working Of Quantum Computer
5 Why so Faster
6 Advantages
7 Disadvantages

3. What is Quantum Computing?
Quantum computing is the computer technology based
on the principles of quantum theory, which explains the
nature and behaviour of energy and matter on the
quantum (atomic and subatomic) level.
Quantum computing is a rapidly-emerging technology
that harnesses the laws of quantum mechanics to solve
problems too complex for classical computers.

4. Why do we need quantum computers?
When scientists and engineers
encounter difficult problems, they
turn to supercomputers. These
are very large classical
computers, often with thousands
of classical CPU and GPU cores.
However, even supercomputers
struggle to solve certain kinds of
problems.
If a supercomputer gets stumped, that's
probably because the big classical machine
was asked to solve a problem with a high
degree of complexity. When classical
computers fail, it's often due to complexity
Complex problems are problems with lots of
variables interacting in complicated ways. At
this stage we need Quantum Computer .

5. What special about Quantum computer
While a bit, or binary digit, can have a value
either 0 or 1, a Qubit can have a value that is
either 0, 1 or a quantum superposition
of 0 and 1.
The state of a single qubit can be described by
a two-dimensional column vector of unit norm,
that is, the magnitude squared of its entries
must sum to 1. This vector, called the quantum
state vector, holds all the information needed
to describe the one-qubit quantum system just
as a single bit holds all of the information
needed to describe the state of a binary
variable.

6. Rather than performing each calculation in turn on the current
single state of its bits, as a classical computer does, a quantum
computer's sequence of qubits can be in every possible
combination of 1s and 0s at once.
 This allows the computer to test every possible solution
simultaneously and to perform certain complex calculations
exponentially faster than a classical computer.
One curious feature of a qubit is that measuring it causes it to
"collapse" into a single classical known state—0 or 1 again—
and lose its quantum properties.

7.  Many quantum algorithms are non-deterministic; they find
many different solutions in parallel, only one of which can be
measured, so they provide the correct solution with only a certain
known probability.
Running the calculation several times will increase the chances
of finding the correct answer but also may reduce quantum
computing's speed advantage

9. A classical processor uses bits to perform its operations. A quantum computer
uses qubits (CUE-bits) to run multidimensional quantum algorithm.
Superfluids
Your desktop computer likely uses a fan to get cold enough to work. Our
quantum processors need to be very cold – about a hundredth of a degree
above absolute zero. To achieve this, we use super-cooled superfluids to create
superconductors.
Superconductors
At those ultra-low temperatures certain materials in our processors exhibit
another important quantum mechanical effect: electrons move through them
without resistance. This makes them "superconductors."
How do quantum computers work?

10. Control
Our quantum computers use Josephson junctions as superconducting qubits. By
firing microwave photons at these qubits, we can control their behavior and get them
to hold, change, and read out individual units of quantum information.
Superposition
A qubit itself isn't very useful. But it can perform an important trick: placing the
quantum information it holds into a state of superposition, which represents a
combination of all possible configurations of the qubit. Groups of qubits in
superposition can create complex, multidimensional computational spaces. Complex
problems can be represented in new ways in these spaces.
Entanglement
Entanglement is a quantum mechanical effect that correlates the behavior of two
separate things. When two qubits are entangled, changes to one qubit directly impact
the other. Quantum algorithms leverage those relationships to find solutions to
complex problems .

11. Why quantum computers are faster
Let's look at example that shows how quantum computers can
succeed where classical computers fail:
A supercomputer might be great at difficult tasks like sorting
through a big database of protein sequences, but it will struggle to
see the subtle patterns in that data that determine how those
proteins behave.
Proteins are long strings of amino acids that become useful
biological machines when they fold into complex shapes. Figuring
out how proteins will fold is a problem with important implications for
biology and medicine.

12. A classical supercomputer might try to fold a protein with brute force, leveraging its
many processors to check every possible way of bending the chemical chain before
arriving at an answer. As the protein sequences get longer and more complex, the
supercomputer stalls. A chain of 100 amino acids could theoretically fold in any one
of many trillions of ways. No computer has the working memory to handle all the
possible combinations of individual folds.
Quantum algorithms take a new approach to these sorts of complex problems --
creating multidimensional spaces where the patterns linking individual data points
emerge. In the case of a protein folding problem, that pattern might be the
combination of folds requiring the least energy to produce. That combination of folds
is the solution to the problem.
Classical computers can not create these computational spaces, so they can not
find these patterns. In the case of proteins, there are already early quantum
algorithms that can find folding patterns in entirely new, more efficient ways, without
the laborious checking procedures of classical computers. As quantum hardware
scales and these algorithms advance, they could tackle protein folding problems too
complex for any supercomputer.

13. Faster computations:-
These type of computers can perform computation at a much faster rate
than normal computers. Quantum computers have computation power
higher than supercomputers also. They can process data at 1000 times
faster than normal computers and supercomputers. Some calculations if
performed by a normal computer can take 1000 years is done by quantum
computers in a few seconds.
Best for simulation:-
Quantum computers are best for doing data simulation computing. There
are many algorithms created that can simulate various things like weather
forecasting, chemical simulation etc.
Advantages

14. Medicine creation:-
These type of computers can work better in the medical field. They can detect
diseases and can create a formula for medicines. Different type of diseases can
be diagnosed and tested in scientific laboratories using these computers.
Google search:-
Quantum computers are used by Google to refine searches. Now every search
on Google can speed up by using these computers. Most relevant results can
be populated using quantum computing.

15. High privacy:-
These computers can make high encryption and is good at
cryptography. It is impossible to break the security of quantum
computers. Recently China has launched a satellite that uses quantum
computing and china claimed that this satellite cannot be hacked.

16. Disadvantages
.
Algorithm creation:-
For every type of computation, it needs to write a new
algorithm. Quantum computers cannot work as classical
computers, they need special algorithms to perform tasks
in their environment.
The low temperature needed:-
As the processing in these computers is done very deeply
so it needs a temperature of negative 460 degrees F. This
is the lowest temperature of the universe and it is very
difficult to maintain that temperature.

17.  Not open for public:-
Due to the high range price they are not available for public use. Also, the
errors in these type of computers are high because they are still in the
development phase. Quantum computers work fine in 10 qubits but after
increasing qubits like 70 qubits, the accuracy is not right.

18. Applications of Quantum Computing
1. Improving Cancer Treatment
2. Optimizing Traffic Flow
3. Quantum communication
4. Simulate Molecules
5. Make AI More Human-like
6. Forecasting Weather
7. Customized Advertising

19. Conclusion
Conclusion Quantum computing is a relatively new and
rapidly-growing field that holds limitless potential for
solving complex problems. As we move further into
the future, quantum computers will become an even
more important part of our technological arsenal,
allowing us to solve problems much faster than
traditional computers.

20. Reference
www.google.com
www.wikipedia.org
www.ibm.com

21. Thanks